Abstract: Sand-dust storms are common in Tarim Basin, Sand and dust are the main materials of the atmospheric aerosol. The analysis on the collected samples of aerosol shows that the atmospheric TSP content during the sand-dust storms is much higher than that during the periods without duststorms. During the duststorm on April 15, 2001, the atmospheric TSP content was 2, 044.33μg/m³ over Aksu Station, during the period without duststorm (March 23, 2001), however, it was 332.19μg/m³; during the duststorm on April 20, 2001, it was 19, 865.46μg/m³ over Cele Station, whereas it was only 212.7μg /m³ during the period without duststorm (March 24, 2001).
The proportion of the coarse particles in aerosol increases evidently during sand-dust storms. For example, the percentage by weight of the coarse particles (＞7. 0μm) in aerosol increased for 6% during the sand-dust storm on March 23, 2001 than that without duststorm (March 20, 2001) over Cele Station, the peak values varied in a range of 4.7～7. 0μm. The atmospheric load increased during the sand-dust storm, the weight content of the coarse particles was higher than that of the fine ones, the peak values of the particles in the different sizes did not change over Aksu Station, but they changed to ＞11.0μm over Cele Station. The percentages of the fine particles are obviously different between the Cele and Aksu stations. During the sand-dust storm on March 18, 2001, the percentage by weight of the fine particles in aerosol over Cele Station was 0.12% less than that without duststorm (March 20, 2001) ; during the sand-dust storm on April 15, 2001, the percentage by weight of the fine particles in aerosol over Aksu Station was 0.8% higher than that without duststorm (March 26, 2001). The increase of the percentage of fine particles in aerosol over Aksu Station during sand-dust storms shows that the local sand and dust materials, especially the fine particles, are abundant and easy to be carried into the atmosphere under strong wind. Whereas the percentage of coarse particles in aerosol over Cele Station increases obviously during sand-dust storms because this area is close to a sand desert. The elements in atmospheric aerosol can reveal their sources to a certain extent. The curves of the spectrum distribution of Al, etc., in the aerosol samples collected from these two places are unimodal, and the maximum values of the content vary in a range of 4.7～7. 0μm, which reveal that the atmospheric aerosol particles over the localities are mainly from the local sand sources. According to the analyzed results of the aerosol samples collected at the sampling platforms of 7 and 17 m in height respectively at Aksu Station, the contents of all the elements in the aerosol samples are quite similar, i. e. being independent of height, however, the total content of the aerosol over Aksu Station is much lower than that over Cele Station. The analysis on the richly concentrating factors of the elements in aerosol shows that the contents of all the crust elements in aerosol during the sand-dust storms and duststorms are higher than that during floating dust weather and in the background atmosphere. Moreover, the lower the visibility is, the higher the proportion will be, and the contents of the crust elements are high during all the sand-dust storms.

Key words: Tarim Basin, Aerosol, TSP content, Spectrum analysis, The enrichment factor analysis